Stem cell-derived extracellular vesicle therapy for acute brain insults and neurodegenerative diseases

The emerging role of mesenchymal stem cell-derived extracellular vesicles to ameliorate hippocampal NLRP3 inflammation induced by binge-like ethanol treatment in adolescence

JOURNAL/nrgr/04.03/01300535-202504000-00030/figure1/v/2024-07-06T104127Z/r/image-tiff Our previous studies have reported that activation of the NLRP3 (NOD-, LRR- and pyrin domain-containing protein 3)-inflammasome complex in ethanol-treated astrocytes and chronic alcohol-fed mice could be associated with neuroinflammation and brain damage. Mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) have been shown to restore the neuroinflammatory response, along with myelin and synaptic structural alterations in the prefrontal cortex, and alleviate cognitive and memory dysfunctions induced by binge-like ethanol treatment in adolescent mice. Considering the therapeutic role of the molecules contained in mesenchymal stem cell-derived extracellular vesicles, the present study analyzed whether the administration of mesenchymal stem cell-derived extracellular vesicles isolated from adipose tissue, which inhibited the activation of the NLRP3 inflammasome, was capable of reducing hippocampal neuroinflammation in adolescent mice treated with binge drinking. We demonstrated that the administration of mesenchymal stem cell-derived extracellular vesicles ameliorated the activation of the hippocampal NLRP3 inflammasome complex and other NLRs inflammasomes (e.g., pyrin domain-containing 1, caspase recruitment domain-containing 4, and absent in melanoma 2, as well as the alterations in inflammatory genes (interleukin-1β, interleukin-18, inducible nitric oxide synthase, nuclear factor-kappa B, monocyte chemoattractant protein-1, and C-X3-C motif chemokine ligand 1) and miRNAs (miR-21a-5p, miR-146a-5p, and miR-141-5p) induced by binge-like ethanol treatment in adolescent mice. Bioinformatic analysis further revealed the involvement of miR-21a-5p and miR-146a-5p with inflammatory target genes and NOD-like receptor signaling pathways. Taken together, these findings provide novel evidence of the therapeutic potential of MSC-derived EVs to ameliorate the hippocampal neuroinflammatory response associated with NLRP3 inflammasome activation induced by binge drinking in adolescence.

Treatment of severe traumatic brain injury with human bone marrow mesenchymal stem cell extracellular vesicles: a case report

OBJECTIVE

Extracellular vesicles (EVs) derived from regenerative mesenchymal stem cells might safely treat traumatic brain injury (TBI). We evaluated the safety and efficacy of a human bone marrow derived mesenchymal stem cell EVs (hBM-MSC EV) investigational product (IP) in a patient with severe TBI.

DESIGN

A single case study employing an IP with a strong safety profile in over 200 patients.

METHOD

The patient was dosed intravenously three times/week in the first week of six successive months. Functional Independence Measure (FIM) and Functional Assessment Measure (FAM) were performed to quantify effects. Safety monitoring was performed every week for nine months.

RESULTS

No adverse events occurred. Within eight weeks FIM and FAM scores improved by 48-55% and were sustained for the entire 36 weeks. All specific outcome items assessed by FIM and FAM that were initially low showed sustained improvements ranging from 41% to 233%, with the greatest improvements seen in locomotion, mobility and cognitive function.

CONCLUSION

After moderate improvement with conventional therapy, the substantial improvement observed following introduction of the IP suggests that hBM-MSC EVs may offer a novel and safe means to improve TBI patient outcomes. Appropriate randomized, controlled clinical trials to conclusively evaluate this therapeutic option are indicated.

Advancements in the treatment of cerebral ischemia-reperfusion injury: Acupuncture combined with mesenchymal stem cells transplantation

Cerebral ischemia-reperfusion injury (CIRI) constitutes a significant etiology of exacerbated cerebral tissue damage subsequent to intravenous thrombolysis and endovascular mechanical thrombectomy in patients diagnosed with acute ischemic stroke. The treatment of CIRI has been extensively investigated through a multitude of clinical studies. Acupuncture has been demonstrated to be effective in treating CIRI. Recent 5 years studies have identified potential mechanisms of acupuncture, including regulation of autophagy, promotion of angiogenesis, inhibition of inflammation and apoptosis, modulation of cell activation, neuroplasticity regulation, and promotion of nerve regeneration. The transplantation of mesenchymal stem cells (MSCs) can effectively suppress apoptosis, modulate immune responses, and enhance the proliferation and migration of endogenous neural stem cells (NSCs), thereby compensating for the NSCs deficiency following cerebral ischemia/reperfusion injury. The combination of acupuncture and MSCs transplantation demonstrates superiority over individual treatments, significantly enhancing the survival rate of MSCs. Moreover, it facilitates the secretion of various cytokines to promote their homing and differentiation into functional neurons, thereby providing a novel approach for clinical treatment of CIRI.

Exploring the potential of MFG-E8 in neurodegenerative diseases

Milk fat globule-epidermal growth factor 8 (MFG-E8) is a multifunctional glycoprotein regulating intercellular interactions in various biological and pathological processes. This review summarizes the effects and mechanisms of MFG-E8 in neurodegenerative diseases (NDDs), emphasizing its roles in inflammation, apoptosis, and oxidative stress. In this review, will also explore the potential of MFG-E8 as a diagnostic biomarker and its therapeutic applications in neurodegenerative disorders. Recent studies have revealed intriguing characteristics of using MFG-E8 as a potential drug for treating various brain disorders. While the discovery, origin, expression, and physiological functions of MFG-E8 in various organs and tissues are well defined, its role in the brain remains less understood. This is particularly true for NDDs, indicating unmet medical needs. Elucidating its role in the brain could position MFG-E8 as a potential treatment for NDDs.

Cell-cell communication: new insights and clinical implications

Multicellular organisms are composed of diverse cell types that must coordinate their behaviors through communication. Cell-cell communication (CCC) is essential for growth, development, differentiation, tissue and organ formation, maintenance, and physiological regulation. Cells communicate through direct contact or at a distance using ligand-receptor interactions. So cellular communication encompasses two essential processes: cell signal conduction for generation and intercellular transmission of signals, and cell signal transduction for reception and procession of signals. Deciphering intercellular communication networks is critical for understanding cell differentiation, development, and metabolism. First, we comprehensively review the historical milestones in CCC studies, followed by a detailed description of the mechanisms of signal molecule transmission and the importance of the main signaling pathways they mediate in maintaining biological functions. Then we systematically introduce a series of human diseases caused by abnormalities in cell communication and their progress in clinical applications. Finally, we summarize various methods for monitoring cell interactions, including cell imaging, proximity-based chemical labeling, mechanical force analysis, downstream analysis strategies, and single-cell technologies. These methods aim to illustrate how biological functions depend on these interactions and the complexity of their regulatory signaling pathways to regulate crucial physiological processes, including tissue homeostasis, cell development, and immune responses in diseases. In addition, this review enhances our understanding of the biological processes that occur after cell-cell binding, highlighting its application in discovering new therapeutic targets and biomarkers related to precision medicine. This collective understanding provides a foundation for developing new targeted drugs and personalized treatments.

Applications of Stem Cell-Derived Extracellular Vesicles in Nerve Regeneration

Extracellular vesicles (EVs), including exosomes, microvesicles, and other lipid vesicles derived from cells, play a pivotal role in intercellular communication by transferring information between cells. EVs secreted by progenitor and stem cells have been associated with the therapeutic effects observed in cell-based therapies, and they also contribute to tissue regeneration following injury, such as in orthopaedic surgery cases. This review explores the involvement of EVs in nerve regeneration, their potential as drug carriers, and their significance in stem cell research and cell-free therapies. It underscores the importance of bioengineers comprehending and manipulating EV activity to optimize the efficacy of tissue engineering and regenerative therapies.

Astrocyte-Derived Extracellular Vesicles for Ischemic Stroke: Therapeutic Potential and Prospective

Stroke is a leading cause of death and disability in the world. Astrocytes are special glial cells within the central nervous system and play important roles in mediating neuroprotection and repair processes during stroke. Extracellular vesicles (EVs) are lipid bilayer particles released from cells that facilitate intercellular communication in stroke by delivering proteins, lipids, and RNA to target cells. Recently, accumulating evidence suggested that astrocyte-derived EVs (ADEVs) are actively involved in mediating numerous biological processes including neuroprotection and neurorepair in stroke and they are realized as an excellent therapeutic approach for treating stroke. In this review we systematically summarize the up-to-date research on ADEVs in stroke, and prospects for its potential as a novel therapeutic target for stroke. We also provide an overview of the effects and functions of ADEVs on stroke recovery, which may lead to developing clinically relevant therapies for stroke.

Mapping knowledge of the stem cell in traumatic brain injury: a bibliometric and visualized analysis

Background

Traumatic brain injury (TBI) is a brain function injury caused by external mechanical injury. Primary and secondary injuries cause neurological deficits that mature brain tissue cannot repair itself. Stem cells can self-renewal and differentiate, the research of stem cells in the pathogenesis and treatment of TBI has made significant progress in recent years. However, numerous articles must be summarized to analyze hot spots and predict trends. This study aims to provide a panorama of knowledge and research hotspots through bibliometrics.

Method

We searched in the Web of Science Core Collection (WoSCC) database to identify articles pertaining to TBI and stem cells published between 2000 and 2022. Visualization knowledge maps, including co-authorship, co-citation, and co-occurrence analysis were generated by VOSviewer, CiteSpace, and the R package "bibliometrix."

Results

We retrieved a total of 459 articles from 45 countries. The United States and China contributed the majority of publications. The number of publications related to TBI and stem cells is increasing yearly. Tianjin Medical University was the most prolific institution, and Professor Charles S. Cox, Jr. from the University of Texas Health Science Center at Houston was the most influential author. The Journal of Neurotrauma has published the most research articles on TBI and stem cells. Based on the burst references, "immunomodulation," "TBI," and "cellular therapy" have been regarded as research hotspots in the field. The keywords co-occurrence analysis revealed that "exosomes," "neuroinflammation," and "microglia" were essential research directions in the future.

Conclusion

Research on TBI and stem cells has shown a rapid growth trend in recent years. Existing studies mainly focus on the activation mechanism of endogenous neural stem cells and how to make exogenous stem cell therapy more effective. The combination with bioengineering technology is the trend in this field. Topics related to exosomes and immune regulation may be the future focus of TBI and stem cell research.

Extracellular vesicles as tools and targets in therapy for diseases

Extracellular vesicles (EVs) are nano-sized, membranous structures secreted into the extracellular space. They exhibit diverse sizes, contents, and surface markers and are ubiquitously released from cells under normal and pathological conditions. Human serum is a rich source of these EVs, though their isolation from serum proteins and non-EV lipid particles poses challenges. These vesicles transport various cellular components such as proteins, mRNAs, miRNAs, DNA, and lipids across distances, influencing numerous physiological and pathological events, including those within the tumor microenvironment (TME). Their pivotal roles in cellular communication make EVs promising candidates for therapeutic agents, drug delivery systems, and disease biomarkers. Especially in cancer diagnostics, EV detection can pave the way for early identification and offers potential as diagnostic biomarkers. Moreover, various EV subtypes are emerging as targeted drug delivery tools, highlighting their potential clinical significance. The need for non-invasive biomarkers to monitor biological processes for diagnostic and therapeutic purposes remains unfulfilled. Tapping into the unique composition of EVs could unlock advanced diagnostic and therapeutic avenues in the future. In this review, we discuss in detail the roles of EVs across various conditions, including cancers (encompassing head and neck, lung, gastric, breast, and hepatocellular carcinoma), neurodegenerative disorders, diabetes, viral infections, autoimmune and renal diseases, emphasizing the potential advancements in molecular diagnostics and drug delivery.

Unraveling the Emerging Niche Role of Extracellular Vesicles (EVs) in Traumatic Brain Injury (TBI)

Extracellular vesicles or exosomes, often known as EVs, have acquired significant attention in the investigations of traumatic brain injury (TBI) and have a distinct advantage in actively researching the fundamental mechanisms underlying various clinical symptoms and diagnosing the wide range of traumatic brain injury cases. The mesenchymal stem cells (MSCs) can produce and release exosomes, which offer therapeutic benefits. Exosomes are tiny membranous vesicles produced by various cellular entities originating from endosomes. Several studies have reported that administering MSC-derived exosomes through intravenous infusions improves neurological recovery and promotes neuroplasticity in rats with traumatic brain damage. The therapeutic advantages of exosomes can be attributed to the microRNAs (miRNAs), which are small non-coding regulatory RNAs that significantly impact the regulation of posttranscriptional genes. Exosome-based therapies, which do not involve cells, have lately gained interest as a potential breakthrough in enhancing neuroplasticity and accelerating neurological recovery for various brain injuries and neurodegenerative diseases. This article explores the benefits and drawbacks of exosome treatment for traumatic brain injury while emphasizing the latest advancements in this field with clinical significance.

New strategies of neurodegenerative disease treatment with extracellular vesicles (EVs) derived from mesenchymal stem cells (MSCs)

Neurodegenerative diseases are characterized by the progressive loss of neurons and intricate interactions between different cell types within the affected regions. Reliable biomarkers that can accurately reflect disease activity, diagnose, and monitor the progression of neurodegenerative diseases are crucial for the development of effective therapies. However, identifying suitable biomarkers has been challenging due to the heterogeneous nature of these diseases, affecting specific subsets of neurons in different brain regions. One promising approach for promoting brain regeneration and recovery involves the transplantation of mesenchymal stem cells (MSCs). MSCs have demonstrated the ability to modulate the immune system, promote neurite outgrowth, stimulate angiogenesis, and repair damaged tissues, partially through the release of their extracellular vesicles (EVs). MSC-derived EVs retain some of the therapeutic characteristics of their parent MSCs, including their ability to regulate neurite outgrowth, promote angiogenesis, and facilitate tissue repair. This review aims to explore the potential of MSC-derived EVs as an emerging therapeutic strategy for neurodegenerative diseases, highlighting their role in modulating disease progression and promoting neuronal recovery. By elucidating the mechanisms by which MSC-derived EVs exert their therapeutic effects, we can advance our understanding and leverage their potential for the development of novel treatment approaches in the field of neurodegenerative diseases.

Role of Exosomes in the Pathogenesis and Theranostic of Alzheimer's Disease and Parkinson's Disease

Alzheimer's disease (AD) and Parkinson's disease (PD) are the most common neurodegenerative diseases (NDDs) threatening the lives of millions of people worldwide, including especially elderly people. Currently, due to the lack of a timely diagnosis and proper intervention strategy, AD and PD largely remain incurable. Innovative diagnosis and therapy are highly desired. Exosomes are small vesicles that are present in various bodily fluids, which contain proteins, nucleic acids, and active biomolecules, and which play a crucial role especially in intercellular communication. In recent years, the role of exosomes in the pathogenesis, early diagnosis, and treatment of diseases has attracted ascending attention. However, the exact role of exosomes in the pathogenesis and theragnostic of AD and PD has not been fully illustrated. In the present review, we first introduce the biogenesis, components, uptake, and function of exosomes. Then we elaborate on the involvement of exosomes in the pathogenesis of AD and PD. Moreover, the application of exosomes in the diagnosis and therapeutics of AD and PD is also summarized and discussed. Additionally, exosomes serving as drug carriers to deliver medications to the central nervous system are specifically addressed. The potential role of exosomes in AD and PD is explored, discussing their applications in diagnosis and treatment, as well as their current limitations. Given the limitation in the application of exosomes, we also propose future perspectives for better utilizing exosomes in NDDs. Hopefully, it would pave ways for expanding the biological applications of exosomes in fundamental research as well as theranostics of NDDs.

Versatility of mesenchymal stem cell-derived extracellular vesicles in tissue repair and regenerative applications

Mesenchymal stem/stromal cells (MSCs) are multipotent somatic cells that have been widely explored in the field of regenerative medicine. MSCs possess the ability to secrete soluble factors as well as lipid bound extracellular vesicles (EVs). MSCs have gained increased interest and attention as a result of their therapeutic properties, which are thought to be attributed to their secretome. However, while the use of MSCs as whole cells pose heterogeneity concerns and survival issues post-transplantation, such limitations are absent in cell-free EV-based treatments. EVs derived from MSCs are promising therapeutic agents for a range of clinical conditions and disorders owing to their immunomodulatory, pro-regenerative, anti-inflammatory, and antifibrotic activity. Recent successes with preclinical studies using EVs for repair and regeneration of damaged tissues such as cardiac tissue, lung, liver, pancreas, bone, skin, cornea, and blood diseases are discussed in this review. We also discuss delivery strategies of EVs using biomaterials as delivery vehicles through systemic or local administration. Despite its effectiveness in preclinical investigations, the application of MSC-EV in clinical settings will necessitate careful consideration surrounding issues such as: i) scalability and isolation, ii) biodistribution, iii) targeting specific tissues, iv) quantification and characterization, and v) safety and efficacy of dosage. The future of EVs in regenerative medicine is promising yet still needs further investigation on enhancing the efficacy, scalability, and potency for clinical applications.

Engineered EVs designed to target diseases of the CNS

Diseases of the central nervous system (CNS) are challenging to treat, mainly due to the blood-brain barrier (BBB), which restricts drugs in circulation from entering target regions in the brain. To address this issue extracellular vesicles (EVs) have gained increasing scientific interest as carriers able to cross the BBB with multiplex cargos. EVs are secreted by virtually every cell, and their escorted biomolecules are part of an intercellular information gateway between cells within the brain and with other organs. Scientists have undertaken efforts to safeguard the inherent features of EVs as therapeutic delivery vehicles, such as protecting and transferring functional cargo, as well as loading them with therapeutic small molecules, proteins, and oligonucleotides and targeting them to specific cell types for the treatment of CNS diseases. Here, we review current emerging approaches that engineer the EV surface and cargo to improve targeting and functional responses in the brain. We summarize existing applications of engineered EVs as a therapeutic delivery platform for brain diseases, some of which have been evaluated clinically.

Stem Cell-derived Extracellular Vesicles: A Promising Nano Delivery Platform to the Brain?

A very important cause of the frustration with drug therapy for central nervous system (CNS) diseases is the failure of drug delivery. The blood-brain barrier (BBB) prevents most therapeutic molecules from entering the brain while maintaining CNS homeostasis. Scientists are keen to develop new brain drug delivery systems to solve this dilemma. Extracellular vesicles (EVs), as a class of naturally derived nanoscale vesicles, have been extensively studied in drug delivery due to their superior properties. This review will briefly present current brain drug delivery strategies, including invasive and non-invasive techniques that target the brain, and the application of nanocarriers developed for brain drug delivery in recent years, especially EVs. The cellular origin of EVs affects the surface protein, size, yield, luminal composition, and other properties of EVs, which are also crucial in determining whether EVs are useful as drug carriers. Stem cell-derived EVs, which inherit the properties of parental cells and avoid the drawbacks of cell therapy, have always been favored by researchers. Thus, in this review, we will focus on the application of stem cell-derived EVs for drug delivery in the CNS. Various nucleic acids, proteins, and small-molecule drugs are loaded into EVs with or without modification and undergo targeted delivery to the brain to achieve their therapeutic effects. In addition, the challenges facing the clinical application of EVs as drug carriers will also be discussed. The directions of future efforts may be to improve drug loading efficiency and precise targeting.

The Evolving Landscape of Potency Assays

There is a "goldilocks" aspect to potency assays. On the one hand, a comprehensive evaluation of the cell product with detailed quantitative measurement of the critical quality attribute/s of the desired biological activity is required. On the other hand, the potency assay benefits from simplification and lean approaches that avoid unnecessary complication and enhance robustness, to provide a reproducible and scalable product. There is a need to balance insightful knowledge of complex biological healing processes with straightforward manufacture of an advanced therapeutic medicinal product (ATMP) that can be administered in a trustworthy cost-effective manner. While earlier chapters within this book have highlighted numerous challenges facing the potency assay conundrum, this chapter offers a forward-looking perspective regarding the many recent advances concerning acellular products, cryopreservation, induced MSC, cell priming, nanotechnology, 3D culture, regulatory guidelines and evolving institutional roles, that are likely to facilitate potency assay development in the future.

Review on the roles of specific cell-derived exosomes in Alzheimer's disease

Alzheimer's disease (AD) is the sixth leading cause of death worldwide and cannot be effectively cured or prevented; thus, early diagnosis, and intervention are important. The importance of exosomes, membrane-bound extracellular vesicles produced in the endosome of eukaryotic cells, in the development, diagnosis, and treatment of AD has been recognized; however, their specific functions remain controversial and even unclear. With the development of exosome extraction, isolation, and characterization, many studies have focused on exosomes derived from different cells and body fluids. In this study, we summarized the roles of exosomes derived from different body fluids and cells, such as neuron, glial, stem, and endothelial cells, in the development, diagnosis, monitoring, and treatment of AD. We also emphasize the necessity to focus on exosomes from biological fluids and specific cells that are less invasive to target. Moreover, aside from the concentrations of classic and novel biomarkers in exosomes, the size and number of exosomes may also influence early and differential diagnosis of AD.

Mesenchymal Stem Cell Application and Its Therapeutic Mechanisms in Intracerebral Hemorrhage

Intracerebral hemorrhage (ICH), a common lethal subtype of stroke accounting for nearly 10–15% of the total stroke disease and affecting two million people worldwide, has a high mortality and disability rate and, thus, a major socioeconomic burden. However, there is no effective treatment available currently. The role of mesenchymal stem cells (MSCs) in regenerative medicine is well known owing to the simplicity of acquisition from various sources, low immunogenicity, adaptation to the autogenic and allogeneic systems, immunomodulation, self-recovery by secreting extracellular vesicles (EVs), regenerative repair, and antioxidative stress. MSC therapy provides an increasingly attractive therapeutic approach for ICH. Recently, the functions of MSCs such as neuroprotection, anti-inflammation, and improvement in synaptic plasticity have been widely researched in human and rodent models of ICH. MSC transplantation has been proven to improve ICH-induced injury, including the damage of nerve cells and oligodendrocytes, the activation of microglia and astrocytes, and the destruction of blood vessels. The improvement and recovery of neurological functions in rodent ICH models were demonstrated via the mechanisms such as neurogenesis, angiogenesis, anti-inflammation, anti-apoptosis, and synaptic plasticity. Here, we discuss the pathological mechanisms following ICH and the therapeutic mechanisms of MSC-based therapy to unravel new cues for future therapeutic strategies. Furthermore, some potential strategies for enhancing the therapeutic function of MSC transplantation have also been suggested.